Knife sharpening and grinding attachment



J1me 1953 A. R. JOHNSON 2,640,303

KNIFE SHARPENING AND GRINDING ATTACHMENT Filed July 2, 1951 3 Sheets-Sheet 1 IN VEN T OR.

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ATTS RN EYE June 2, 1953 A. R. JOHNSON KNIFE SHARPENING AND GRINDING ATTACHMENT Filed July 2, i951 3 Sheets-Shee t 2 IN VEN TOR. flmoz R fafins 0/2,

ATTD RN EYS A. R. JOHNSON KNIFE SHARPENING AND GRINDING ATTACHMENT June 2, 1953 s sheets-sheet 5 Filed July 2, 1951 INVENTOR. flr/YaZd' 7i. c/azzson,

ATTDRN EYS Patented June 2, 1953 UNITED STATES PATENT "OFFICE .SHABPENING AND GRINDING ATTACHMENT Arnold R. Johnson, Underwood, N. Dale.

Applicaticnluly 2, 1951, l'Serial l'No. 234,757

'3Clainrs. (CL-51 135) This invention relates to devices for grinding and sharpening knives particularly kitchen knives, and in particular sharpening and grinding machines for knives and other devices having sharp edges wherein a continuous belt having a grinding outer surface is mounted on vertically positioned pulleys with suitable guides positioned adjacent one of the pulleys for holding knives and the like at proper angles in relation to the grinding .belt and in which resilient take up means .is provided in combination with one of the pulleys for maintaining constant tension in the continuous belt.

The purpose of this invention is to provide a comparatively small, compact grinding machine .for household and domestic .use wherein a knife blade or other device having a sharp edge .is secured by clamping elements against the surface of a grinding :belt with the cutting edge of the blade heldaat a proper angle in relation to the belt.

Various types of grinders have been provided for small knives and particularly kitchen :knives -but where .a knife is held against a grinding wheel it is diificult .for the average layman to hold the knife at the proper angle and knives .are constantly burned and otherwise damaged by inexperienced persons attempting to hold the cutting edges of knives in grinding relation to a grinding wheel or the like. in mind this invention contemplates a knife grinder wherein means is provided for positioning a knife in relation to a grinding element whereby the cutting edge of a knife may readily be ground to the proper angle for efiicient cut- I "ting.

The object of this invention is, therefore, to provide means for forming a small grinding machine so that knives and other sharp edge devices 10]: tools may be correctly positioned in relation to :a grinding element.

Another object of this invention is to provide a knife grinding machine particularly adapted for kitchen use and that is adapted to be operated by the spindle of a conventional mixing or heating machine.

A further object of the invention. is to provide a small grinder for knives and other implements that is particularly adapted for household use, which is of a simple and economical construction.

With these and other obj ects and advantages view the invention embodies a of vertically disposed pulleys carried by a. lease and having an endless belt witha grinding outer surfacetrained over the pulleys, wrtnnieans for maintaining 'con- With this thought i stant "tension in the belt, with means for holding knives and other implements in driving relation to the belt, and with means by which the belt may be rotated. A

Other features and advantages of the invention will appear from the following description taken in connection with the drawings wherein:

Figure 1 "is aside elevational view illustrating the portable grinder with parts broken away and shown in section and in which the grinder is operated by a motor "with ulleys and "a belt.

Figure 2 is a similar view showing a longitudinally disposed section. through the grinding wheel and illustrating a'modification wherein the motor, pulleys and belt are omitted and the grinder is actuated by a spindle of a linker, heater, or the like, said section being taken on line .22 of igure 3. i

Figure 3 is a plan view of the grinder with the parts as shown in Figure 2.

Figure 4 is a cross section through the grinder shown in Figure 3 being taken on 'line 4 4 thereof, I

Figure 5 is a detail illustrating guides forho'lding a knife blade in grinding. position.

Figure 6 is a similar detail showing the position of a guide for holding a blade to obtain a different taper.

Figure '7 is a cross section through the mounting base of the grinder being taken on line 1-1 of Figure .2-

Figure 8 is a cross section taken on line 8 -8 of Figure 2.

Figure 9 is a similar section being taken on line 99 of Figure 3.

Figure 10 is .a detail showing a plan view of a retaining cap for holding a knife blade in the guides with the cutting edges of the knives in grinding relation with the belt.

Figure 1.1 is-a detail similar to that illustrated in Figures 5 and 6 illustrating the use of a mounting strip for holdin the knife blade a grinding position. v

Referring now to the drawings wherein like reference characters denote corresponding parts,

the'kniie grinder, as illustrated in Figure l is formed with a channel-shaped base it having vertically disposedpulleys H and 12 with aband l3 having a grinding outer surface trained over the pulleys. The pulleys are rotated by a motor M carried by a post I5 on the base it and the motor drives the pulley ll through a belt i=6 which is trained over pulleys il and i8.

The post is is mounted on the channel-shaped pass to through a flange t9 -a;nd the motor shaft 26 is connected to the shaft 2i, on the lower end of which the pulley I8 is positioned, by a coupling sleeve 22. The sleeve extends upwardly from the hub 23 on the base I with a friction washer 24 between the upper end of the hub and lower end of the coupling sleeve.

The knife grinder is provided with guides 25 and 26, which in combination with frustro-conical shaped rollers 21 and spring arms 28 retain knives in cutting relation with the grinding surface of the belt or band I 3. Tension is maintained in the grinding belt by a spring 29 which is similar to the spring in the design illustrated in Figure 2.

In the design illustrated in Figures 2 and 3 wherein the grinding machine may be operated by a conventional kitchen mixer or the like a base 30 channel-shaped in cross section is mounted through a plate 3I on a table, stand, or the like with the plate 3| secured in recesses below ribs 32 and 33. The plate 3| is provided with lugs 34 and 35 for mounting the device on the base of a mixer, or the like and the lugs are secured to the plate by screws 35 and 31, respectively and with nuts 38 and 39 on the ends of the screws. Washers 40 and M may be placed between the nuts and lugs and friction washers 42 and '43 are provided between the lugs and under surface of the plate 3I. The plate 3| is secured in position by a screw 44 having a countersunk head 45 and the screw extends through a slot 46 in the web of the channel 30 with the upper end'held .by a nut 41. A

washer 4-8 is positioned between the nut and upper surface of the web. It will be understood that the base 30 may be provided with other suitable means whereby the grinder may be attached to the base of a mixer, heater, or other machine or device.

With the parts arranged in this manner a head pulley 49 with a socket 50 in the upper end is journaled over a cylindrical plug 5|, the lower 3 end of which is provided with an extending stud .52 that is secured in an opening 53 in the web of the base by a stem 54 extended through the member SI and a washer 55,..asshown in Figure 2. 'The lower end of the stem 54v is provided with a set collar 56 having a screw 51 therein. By this means the pulley 49 is journaled on the base and, as illustrated in Figure 2, the pulley is provided with a sleeve 58 that may be formed of rubber or other suitable material.

The pulley 49 may be driven from a mixer or the like with the spindle 59 of the mixer extended into a coupling member 60 in the upper end of an auxiliary spindle El. 7

A grinding belt 62 is positioned over the pulley ,49 and also held over a similar tail pulley 63, at the opposite end, that is mounted on a spindle 64 having a base 85 and the spindle is held in a yoke 66 from which a bar 61 extends. The bar 61 extends through an opening 68 in a guide post 68 on the base 30 and a spring "HI urges the yoke away from the guide post whereby the grinding belt is continuously held in tension.

The post 69 is mounted on the web of the base 30 by a screw II and the spindle 64 is mounted through the base 65 of the channel-shaped base 30 by screws 12 and I3 which extend through flanges I4 extended from the base 65, and through washers I5 and I1 in a slot 18 of the web of the base, the lower ends of the screws being held in a plate I9. The plate 19 is slidably mounted in slots in parallel ribs 80 and 8| positioned on the under surface of the web of the base. The spindle 64 is also provided with a stud 82 that extends through the plate I9.

A spring I5 is placed around the screw '13 in the washer 11 for urging the outer side of the base 65 upwardly so as to tilt pulley B3 somewhat in order to run the belt 62 high or low on the pulleys 49 and 63 whereby full use of the grinding belt is obtained. The position of the belt is, therefore, regulated by the screw 13.

An arm 82' on the upper end of the yoke 66 is secured to the upper end of the spindle 64 with a screw 83 and the arm 84 forming the lower part of the yoke is provided with fingers 85 that extend over the base 65 of the spindle.

The pulley 63 is also covered with a sleeve 86, similar to the sleeve 58 which is formed of rubber or other suitable resilient material.

In order to correctly position knives and other implements in relation to the grinding belt 62 the machine is provided with a guide 81 which, through grooves 89 and 90 in the sides, is slidably held on tongues 9i and 92 that extend inwardly from flanges 93 and 94, respectively, on the upper edges of the base 30 and this guide is secured in position by a screw 95.

The guide is provided with screws 96 and 91, the heads of which are off-center, and these screws are positioned to engage projections II 8 and I89 of arms I05 and H3, to limit the positionscf the tapered rollers I31 and H9 in relation to the belt 82.

The block 87 is provided with an upwardly extended guide 98 that is positioned on the center of the grinding belt and the edges of the guide 98 are provided with projections 59 and I08 which facilitate holding the blade of a knife against the surface of the guide and grinding belt.

One side of the block 81 is also provided with a guide IUI having a ridge I82 on the upper end and a similar guide I03 on the opposite side of the block is provided with a corresponding ridge I04.

The device is provided with an arm I05 that is pivotally mounted by a screw I 06 onthe block 8! and the arm I05 is provided with a frustroconical guiding member IB'I that is mounted on a pin I08.

The arm I05 is provided with an extension I09 that engages the head of the screw 96 to limit inward movement of the arm and conical shaped member I01 and the arm is resiliently held by a spring positioned around the screw I96 and having an end H0 bearing against the extension I09 and also an end III the end of which extends into an opening I I2 in the block 81.

A similar spring is provided for holding an arm II 3 that is pivotally mounted on the opposite side of block 87 by a screw H4 and this spring is provided with an arm H5 the end of which extends into an opening H6 in the block ill, and also an arm II! that bears against an extension H8. The arm H3 bears against the head of the screw 97.

The arm I I3 is also provided with a conical shaped member H9 that is mounted on a pin I20 and, as illustrated in Figures 5 and 6 these parts are positioned to hold knife blades, as indicated by the numerals I 2I and I22 in grinding relation to the face of the grinding belt as indicated by the dotted lines I23 and I24, in Figures 5 and 6, respectively.

The machine is also provided with a triangular shaped cap having wedge-shaped arms I25 and I26 connected by a cross member I21, as shown in Figure 10 and this cap is positioned over the guide for retaining knife blades and the like in grinding position with the cutting edges of knife blades being held by flanges I 28 and I29 on the upper edges of the arms I25 and I25 and also by a flange I30 on the cross member 121. By this means the blades 13! of knives may readily be held in position as the cutting edges are ground by the belt 62.

With the parts arranged in this manner knives and other implements having sharp cutting edges may readily be positioned to engage the surface of the belt and, as illustrated in Figures 5, 6 and 11, the blades may be held in position and ground with the cutting edges ground to the most efiicient angles for cutting.

It will be understood that holding devices such as the guides 98, I0! and I03 with the frustroconical shaped members I01 and H9 are also used in combination with the grinder shown in Figure 1 whereby knives may be held on the belt l3 with the knives positioned as illustrated in Figures 5, 6 and 11.

The unique knife grinding machine of this invention may, therefore, be driven by an independent motor or may be operated by a spindle or shaft of a food mixer, beater, or other motor operated kitchen machine.

It will be understood that other modifications may be made in the design and arrangement of the parts without departing from the spirit of the invention.

What is claimed is:

1. In a grinder, the combination which comprises a base, channel-shaped in cross section, a vertically positioned head pulley journaled on the base, a vertically positioned tail pulley joumaled on a spindle slidably mounted on the base, a belt having a grinding outer surface trained over the said pulleys, means resiliently urging the tail pulley away from the head pulley, means rotating the said head pulley for driving the belt, guide elements positioned at the sides of the said head pulley, means retaining cutting blades on the said guide elements, frustroconical shaped members positioned to coact with the guide members for holding blades, and means resiliently urging said frustro-conical shaped members toward the grinding belt.

2. In a knife grinder, the combination which comprises a base channel-shaped in cross section, a vertically positioned head pulley joumaled on the base, a vertically positioned tail pulley slidably mounted on the base, means resiliently urging the tail pulley away from the head pulley, a belt having a grinding outer surface trained over the said pulleys, vertically positioned guides mounted on the base and positioned to coact with the belt for retaining knives in grinding relation to the belt, arms pivotally mounted on the base and spaced from the guides, frustroconical shaped members carried by the arms and positioned to engage knives positioned in the guides, resilient means urging the arms with the frustro-conical shaped members thereon toward the belt, and means limiting inward movement of the arms, said head pulley having a socket in the upper end by which the pulley is rotated by a spindle of a mixer or the like.

3. In a knife grinder, the combination which comprises a base channel-shaped in cross section, a vertically positioned head pulley journaled on the base, a vertically positioned tail pulley slidably mounted on the base, means resiliently urging the tail pulley away from the head pulley, a belt having a grinding outer surface trained over the said pulleys, vertically positioned guides mounted on the base and positioned to coact with the belt for retaining knives in grinding relation to the belt, arms pivotally mounted on the base and spaced from the guides, frustro-conical shaped members carried by the arms and positioned to engage knives positioned in the guides, resilient means urging the arms with the frustro-conical shaped members thereon toward the belt, means limiting inward movement of the arms, a motor mounted on the base, and means rotating the head pulley for driving the belt by the motor.

ARNOLD R. JOHNSON.

References Cited in the file of this patent -UNITED STATES PATENTS Number Name Date 557,462 Wenchel Mar. 31, 1896 598,671 Driver Feb. 8, 1898 961,554 Sweet June 14, 1910 1,018,562 Holmes Feb. 27, 1912 1,286,560 Docter Dec. 3, 1918 1,628,531 Carlson May 10, 1927 2,161,992 Battocchi June 13, 1939 2,222,361 Burns Nov. 19, 1940 2,322,459 Lippold June 22, 1943 2,334,960 Roth et a1. Nov. 23, 1943 

